This invention relates to a method and apparatus for determining the alignment of motor vehicle components, and more particularly, to a method and apparatus for displaying a three-dimensional model representing the motor vehicle wheels undergoing alignment, together with information indicia corresponding to actual alignment orientations of the motor vehicle wheels relative to the vehicle chassis as determined by alignment equipment.
Various different display methods and devices have been utilized to aid automotive technicians in determining the alignment and angular relationships of motor vehicle wheels on a vehicle undergoing service relative to the vehicle chassis. When alignment testing equipment was first introduced, the equipment merely provided the technician with a single number, indicative, for a single motor vehicle wheel, of the number of degrees the wheel was out-of-alignment with respect to a predetermined reference plane. This number might be either positive or negative, corresponding to the direction in which the wheel was currently aligned. These types of displays were often not dynamic, in that that technician would be required to make some adjustments to the vehicle alignment, and then re-test the vehicle alignment to determine the results of his adjustments. Eventually, equipment was introduced with the capacity to continually update the display to provide the technician with real-time information corresponding to the effects of any adjustments made to the vehicle alignment.
Alternative methods of displaying the information obtained from wheel alignment testing equipment were developed to provide the technician with additional information. For example, with the advent of computerized testing equipment, two-dimensional bar-graph displays were developed to provide the technician with a visual indication of when a motor vehicle wheel was outside of acceptable tolerance limits for alignment relative to the vehicle chassis. These displays provide the technician with an indicator mark corresponding to the current alignment or angular relationship of the motor vehicle wheel, displayed against a bar-graph representing in-tolerance and out-of-tolerance alignment measurements. As the technician adjusts the wheel alignment, the indicator mark shifts correspondingly, and may be observed in relation to the in- and out-of tolerance positions, providing the technician with a visual indication of wheel alignment.
However, despite the significant advantages over the simple numeric displays offered by the two-dimension bar-graph display, the display system fails to provide the operator with an intuitive representation of which angular relationships the bar-graphs represent. For example, without the appropriate labels, it is not possible to distinguish between the bar-graphs representative of camber, caster, and toe angles. Accordingly, motor vehicle wheel alignment displays have been produced which provide a quasi-three dimensional view as seen in FIG. 2A of both U.S. Pat. Nos. 5,535,522 and 5,724,743 to Jackson.
Quasi-three dimensional views, such as shown in the '522 and '743 patents, overlays a static perspective view of the motor vehicle wheels and suspension system with dynamic alignment and angular relationship information obtained from a wheel alignment system. While the static perspective image never changes, the dynamic alignment and angular relationship information, in the form of vectors, is altered on the display to correspond to any changes the technician might make to the vehicle wheel alignment. While such displays provide the technician with a more intuitive display of the angular relationships involved in the alignment of motor vehicle wheels, they suffer from several drawbacks. First, due to the static nature of the background image, some of the wheel alignment angle vectors displayed are not positioned at an optimum angle for viewing, and may be partially obscured by the various wheel and suspension components shown in the static image. Second, the static background is misleading to a technician, as it never varies even if a motor vehicle wheel is drastically out of alignment with respect to the remaining motor vehicle wheels and chassis. This can lead to a false impression that the wheels are properly aligned if a technician does not pay careful attention to the positioning of the alignment vectors. Finally, in an attempt to optimize the viewing of all the associated wheel alignment vectors, the motor vehicle wheels shown in the static image are not shown in the correct perspective view, but rather are distorted in size relations.
Accordingly, there is a need in the industry for a display device and method capable of displaying a real-time three-dimensional image of a motor vehicle wheel and suspension system, together with accurately determined wheel alignment and angular relationship information, in such a manner as to provide a technician with an intuitive and flexible representation of the actual alignment and angular relationships.